Problem: $ { \left[\begin{array}{rrr}{0} & {4} & {4} \\ {1} & {-2} & {1}\end{array}\right]+\left[\begin{array}{rrr}{3} & {0} & {3} \\ {0} & {-2} & {0}\end{array}\right] = {?} } $
Explanation: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rrr}{0}+{3} & {4}+{0} & {4}+{3} \\ {1}+{0} & {-2}+{-2} & {1}+{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{3} & {4} & {7} \\ {1} & {-4} & {1}\end{array}\right]}$